Providing a catlyst free diamond layer on drilling cutters

Abstract

A method of making a polycrystalline diamond compact including providing a layer of graphene on top of a sintered PCD and transforming the graphene at high pressure and temperature into diamond that is free of metal catalyst. A method of making PCD by providing a layer of graphene powder on top of a layer of diamond powder and sintering at high pressure and temperature to transform the graphene into diamond that is free of metal catalyst at the surface.

What is claimed is: 
     
         1 . A cutting element for a tool, comprising:
 a substrate;   a polycrystalline diamond table bonded to the substrate; and   a diamond volume substantially free of catalytic material attached to the polycrystalline diamond table, wherein the polycrystalline diamond table is sandwiched between the substrate and the diamond volume substantially free of catalytic material, wherein the substantially free of catalytic material on diamond volume is not a result of a leaching process.   
     
     
         2 . The cutting element of  claim 1 , wherein the diamond volume substantially free of catalytic material is converted from graphene or fullerene. 
     
     
         3 . The cutting element of  claim 1 , wherein catalytic material is present as a sintering aid in manufacturing the polycrystalline diamond table. 
     
     
         4 . The cutting element of  claim 1 , wherein the substrate is a cemented carbide substrate. 
     
     
         5 . The cutting element of  claim 1 , wherein the polycrystalline diamond table is rich in catalytic material. 
     
     
         6 . The cutting element of  claim 1 , wherein the polycrystalline diamond table is a leached polycrystalline diamond table. 
     
     
         7 . The cutting element of  claim 1 , wherein the polycrystalline diamond table is double pressed to the substrate. 
     
     
         8 . The cutting element of  claim 1 , wherein the diamond volume substantially free of catalytic material has a bevel at a peripheral edge. 
     
     
         9 . A method of making a cutting element, comprising:
 positioning a diamond volume between a substrate and graphene; and   converting graphene into a coherent layer bound onto the diamond volume and the substrate.   
     
     
         10 . The method of  claim 9 , wherein the diamond volume is double pressed onto the substrate. 
     
     
         11 . The method of  claim 9 , wherein the bonding includes pressing the graphene onto the diamond volume and the substrate at high pressure and high temperature. 
     
     
         12 . The method of  claim 10 , wherein a first press is at higher temperature than catalyst melting point and a second press is at a temperature lower than catalyst melting point. 
     
     
         13 . The method of  claim 9 , wherein the coherent layer comprises polycrystalline diamonds. 
     
     
         14 . The method of  claim 9 , wherein the diamond volume acts as seeds for graphene to convert to polycrystalline diamond. 
     
     
         15 . A method of making a cutting element, comprising:
 positioning a diamond volume onto a substrate;   disposing a pill adjacent to the diamond volume distal from the substrate; and   sintering the pill to form a layer adhered to diamond volume and secured to the substrate.   
     
     
         16 . The method of  claim 15 , wherein the adhered layer comprises polycrystalline diamond. 
     
     
         17 . The method of  claim 15 , wherein the pill is a graphene pill or a fullerene pill. 
     
     
         18 . The method of  claim 15 , wherein sintering further includes converting the pill to polycrystalline diamond. 
     
     
         19 . The method of  claim 15 , wherein the diamond volume comprises a diamond table. 
     
     
         20 . The method of  claim 19 , wherein the diamond table is rich in catalytic material. 
     
     
         21 . The method of  claim 19 , wherein the diamond table is substantially leached. 
     
     
         22 . The method of  claim 19 , wherein the diamond table is double pressed onto the substrate. 
     
     
         23 . The method of  claim 22 , wherein the double press onto the substrate includes a first press at higher temperature than catalyst melting point and a second press at temperature lower than catalyst melting point.